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What's the simplest entity that can have fun?

  1. Aug 25, 2016 #1
    My friend asked me this question the other day , and although it sounds simple and foolish i was unable to find an answer to it even after hours of internet research .
    my friend said that us humans can feel joy and euphoria and that's actually what drives most of us in life .
    now less intelligent creatures like dogs , cats and so on .. can also feel "joy" . now he asked what's the simplest architecture or physical manifestation that can "Feel" or be at a state of "joy" .
    and can an entity not be intelligent at all but feel joy ?

    he also said that imagine there was an isolated brain , that is at a continuous state of extreme euphoria , without being able to interact with the external world or anything , it's just an entity having fun ... how simple can that entity get ?

    thank you .
  2. jcsd
  3. Aug 25, 2016 #2


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    Interesting question, although it may be difficult to define "fun" in some objective way.

    One related question that maybe is easier to answer is what is the simplest form of life that "plays". It's easy to see many mammals play with each other (chasing, being chased, rolling around with play biting, etc.), and I've seen some birds do some things that look like play. Do reptiles exhibit any playful behaviors?
  4. Aug 25, 2016 #3
    thank you for your attention sir .
    i don't know much about reptiles i am sorry for that . but the problem is about feelings in general , what's the simplest biological or physical manifestation that can have feelings . the other odd point is the fact that us humans need to accomplish our roles in life (eat,survive,reproduce...) in order to get joy ("euphoria") but what if you get an entity that doesn't have to do any of that but that is instead at a continuous state of "joy" .
    as for the definition of joy , i actually can't set an exact definition for it but i think you understood what i mean with it .
  5. Aug 25, 2016 #4
    I guess the idea of 'joy' or 'fun' implies pleasure, and that I think would have to be limited to the animal kingdom.
    Moreso complex animals with somewhat evolved brains, and social behaviours.
    So I think we are at a minimum looking at the more highly developed mammals, maybe some birds and fish.
    I don't expect a plant would experience 'joy' in any normal use of the word if it gets dry, then rain comes.
  6. Aug 25, 2016 #5


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    To me this involves several different levels of analysis:
    1) Philosophical: questions of the nature of mind and emotions (expanding "fun" to feeling any kid of emotion).
    Personally, I consider other people (and some animals) to have an internal psychology similar to my own, but this is an assumption.

    2) Assuming #1 then it would seem that indeed other animals seem to have emotions. To many people, it would seem reasonable to extend this from humans to other animals like mammals and birds. Including simpler organisms might be questionable to increasing numbers of people.

    3) Feeling any kind of emotion requires being able to sense the internal states of one's nervous system. A minimal requirement for this would be a information processing loops in the nervous system. Probably most (if of not all) nervous systems have this. These loops would certainly be found in many invertebrate nervous systems such as insects and things as simple as the C. elegans worm (having a total of about 1,000 cells in its body). Probably also in coelenterates (jellyfish, anenomes, etc.).

    There's a lot of space between #2 and #3.
    Last edited: Aug 25, 2016
  7. Aug 25, 2016 #6

    Fervent Freyja

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    These white blood cells must be having a blast...

    What I've gathered from my own perspective while observing some eukaryotes, is that they are indeed social and exhibit behaviors like 'curiosity' about their surroundings and other organisms; especially, when they come near another of their kind, they will brush against each another (possibly an attempt to distinct the other from food or predators) and spend a few seconds around before moving on to feed!

    A paramecium annoying a moss piglet! These critters are adorable, my little girl 'found' her first one months ago (with my assistance, but she doesn't need to know that)...

    I would say that all organisms 'feel' some sort of joy at least when feeding!
  8. Aug 25, 2016 #7
    You seem to be talking about sentience--the ability to feel and experience subjectively. A philosophical Pandora box. Feeling "joy" is a sentient experience. Whether 'intelligence' is a prerequisite for sentience (or vice-versa) is open for debate (and we may have to throw 'consciousness' into the mix too). It might not be unreasonable to assume that these things are somehow intertwined. But 'intelligence' is a bit of a value judgement we make, and 'consciousness' is a mystery. Deep down, all animals display similar overarching patterns of homeostasis and behavior. The only thing that differs is complexity.

    Humans are not qualified in any way to judge whether or not other animals are sentient. We don't even understand the mechanisms underlying our own sentience and consciousness. Figure out the explanatory gap first, then we might have a constructive discussion on the subject.

    There is only so much that we can reasonably infer from animal behavior. The only animals whose behaviors give us reasons to assume that they might be sentient are other complex animals, mostly mammals. No less complex biological organisms than humans. Their intelligible and somewhat nuanced behavior often suggests that they are actually processing some kind of feeling like we do. But being mammals ourselves, we may fail to 'empathize' with non-mammal animals as easily.

    Some birds and cephalopods display remarkable intelligence, but it's more difficult to empathize with them on a cognitive or behavioral level. Especially cephalopods because these are very different animals. Their nervous systems are radically different from our own.

    Simpler life forms tend to display a smaller (or more simplistic) range of behaviors, which hardly earns a recognition for sentience or 'high intelligence'. Doesn't mean they are not sentient, though. It cannot be known for a fact whether or not an animal is sentient. It can only be assumed.

    It's not about joy. Humans do what they're built to do just like any other animal, although we do seem to have quite a range for 'free' exploration.

    Doesn't make sense to conjecture an entity that exclusively experiences "joy." Being a subjective experience, a contrast is necessary to warrant the qualitative judgement. Such an entity could hardly qualify as a form of life as we know it anyway.
    Last edited: Aug 25, 2016
  9. Aug 26, 2016 #8
    thank you very much .
  10. Aug 29, 2016 #9
    I'm not really in the biology field, but I've always felt that 'fun', whether in humans or animals is what they do when are in a safe environment, are well-fed and, at that time, have no immediate concerns for survival (eating/running/sleeping).
    In more intelligent mammals, this fun (playing, teasing) might be obvious to us, but not so obvious in animals whose behaviours are not familiar to us.

    I also think feeling joyful (and the associated brain chemistry) at the above conditions is something that evolved over the years to encourage actions which are better for survival. If I constructed a highly advanced AI, I don't think it would 'have fun' at first. It might eventually learn to have fun later on though.

  11. Aug 29, 2016 #10
    'Fun' is 100% defined as a human experience. So it can only be humans.
  12. Aug 29, 2016 #11
    What is conspicuously missing from the arguments in this thread is a discussion of reward and punishment systems in vertebrates. There are well-defined paths and structures in the brain associated with each, and there's also evidence of reciprocal inhibition of each. Furthermore, there is also evidence that the reward an punishment systems in mammals-humans derived from "approach to" and "withdrawal from" neural circuits in earlier vertebrate and even invertebrate phylogeny. One could argue that these approach-withdrawal neural circuits say something about pleasure and pain and I'd say they'd be right. You can also argue that you can trace this push-pull dichotomy as far down the phylogenetic line as you want. In earlier years I did a lot of study on central pattern generators in insects, cephalopods, etc. and there are well-defined neural circuits that define approach and avoidance behaviors and a complicated, but decisively reciprocal action, between the two. These interactions typically involve key neurons or small neuron systems that are identified with specific neurotransmitters such as dopamine, norepinephrine, etc. that appear to be conserved in vertebrate physiology. It's pretty fascinating if you're looking for good reading on a slow TV night, which is pretty much obsolete these days.

    So as far as the simplest entity that can have fun, I'd say it is one that possesses a reward-punishment component to their biology. Plants don't seem to posses this although they can present such "behaviors" as tropisms. But when you are talking about reward-punishment interactions, you are really talking about a logical circuitry of neurons as a definition. I guess you may make a similar argument if you can find some sort of chemical interaction in unicellular organisms that mimic this.
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